Structural surface and thermodynamics analysis of nanoparticles with defects

GAVILÁN ARRIAZU, EDGARDO MAXIMILIANO; GAVILÁN ARRIAZU, EDGARDO MAXIMILIANO; PINTO, OSCAR ALEJANDRO; PINTO, OSCAR ALEJANDRO; GIMÉNEZ, RODRIGO E; GIMÉNEZ, RODRIGO E

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

ROYAL SOC CHEMISTRY

Año: 2020 p. 23148 - 23157

1463-9076

In this work, we analyze the surface structure and the thermodynamics regarding the decorations of nanoparticles with defects, using statistical calculations and Monte Carlo simulations in a complementary way. The results show how the presence of surface defects of the same nature of the nanoparticle induce different sites distributions depending on the density of defects, the geometry and size of the considered nanoparticle. Those distributions are analyzed and characterized in detail for an Icosahedron nanoparticle of different size and density of defects, and then are linked with Monte Carlo simulations to interpret the thermodynamic results. For low temperature or strong attractive interactions conditions, the details emerging from the defective surfaces are manifested as wide plateaus in the isotherm and peaks in the compressibility of the adlayer. Different situation is observed as temperature rises, since the structural details gradually disappear from the thermodynamic measurements, until plateaus and compressibility peaks completely merge for high enough temperature conditions. Adsorption sites distribution, adsorption isotherms, energy per site, compressibility of the adlayer, and other relevant properties are analyzed as a function of the number of defects and the chemical potential. In addition to the icosahedron, cuboctahedron and truncated octahedron geometries are also analyzed.